The present invention relates to exhaust system for use in conjunction with internal combustion engines, and more particularly, to silencers or tuning chambers used in conjunction with a two-cycle internal combustion engine.
Conventional tuning chambers used in conjunction with twocycle engines as employed for example on snowmobiles include an exhaust pipe communicating with the engine exhaust port followed by a diverging conical section, an exhaust chamber, and a converging conical section leading to a tail pipe or stinger. The diverging conical section, exhaust chamber, and converging conical section are collectively referred to as a tuning chamber. Each of these components perform an important function in timing the exhaust from a two-cycle engine to attain the maximum power. This is because the pressure pulse created in the tuning chamber by the flow of exhaust gases therethrough can be advantageously used to increase engine efficiency.
The divergent and convergent conical sections are formed by a rather elaborate stamping die, or hand fabrication process to get the proper shape. The manufacturing process is further complicated by the fact that the length and rate of area change of the conical sections are critical to the performance of the engine and are different for each type of two-cycle engine.
The present invention presents an improved tuning chamber which can be fabricated without the need for expensive stamping dies and fabricating procedures.